1. Field of the Invention
The invention relates to a method for calibrating the internal measurements of an in particular annular body comprising at least partially crystalline or thermoplastic plastic, and/or to an annular body that is calibrated by the method, and/or to an oscillating body for use in the method.
2. Description of the Prior Art
Calibration methods are known that are performed purely mechanically, and in which the parts to be calibrated are typically not heated. For the calibration, a mandrel of defined external dimensions is pressed axially into the interior of an annular body, in order to adjust the internal measurements of this annular body to a desired set-point measurement by plastic deformation of material. The introduction of the mandrel causes local compression of material in the region of the inner surface of the annular body, and the extent of the compression of material is dependent on production tolerances of the annular body in the uncalibrated state. After the mandrel is removed, the material comprising the annular body rebounds, and this rebounding in turn depends on the extent of the prior compression of material. Consequently, the internal measurements of an annular body calibrated in this way still vary relatively greatly. In other words, the desired dimensional tolerances can be attained only somewhat precisely by such a known calibration method. Besides, annular bodies of partially crystalline or thermoplastic plastic are unsuitable for such calibration methods because their material tends to crack. The disadvantageous result is thus that parts are damaged at the outset, or in an extreme case even destroyed.